1. Field of the Invention
The present invention relates to a semiconductor device, such as a power device or high frequency application switching IC, wherein semiconductor circuits having a semiconductor chip and gate resistor are disposed in parallel.
2. Description of the Background Art
Power converting inverter devices are widely used as one kind of power conversion device. For example, an electric motor is normally used as the drive source in an electric vehicle, hybrid vehicle, or the like, and inverter devices are widely utilized in controlling this kind of motor.
A semiconductor device configured of a semiconductor module wherein a plurality of circuit substrates on which is mounted a power device such as an insulated gate bipolar transistor (IGBT) or free wheeling diode (FWD) are disposed, and sealed into a predetermined form using a mold resin material, is used as this kind of power conversion device.
This semiconductor device is such that, as heat is generated from a semiconductor chip, semiconductor chip temperature management is necessary.
Heretofore, a power conversion device wherein temperature detection for protecting a power semiconductor element against heat is carried out in the vicinity of a part in which the power semiconductor element is packaged, and using a temperature detection element disposed in the vicinity of either one of an emitter terminal or a collector terminal of the power semiconductor element has been proposed as this kind of semiconductor device (for example, refer to JP-A-2006-41407).
Also, there has been proposed a power control circuit wherein, when a plurality of IGBT elements are disposed, the gate resistance value of an IGBT element with good cooling efficiency is set high while the gate resistance value of an IGBT element with poor cooling efficiency is set low (for example, refer to JP-A-2006-191774).
Furthermore, there has been proposed a thermistor-incorporating power semiconductor module configured with an inverter, or the like, wherein a plurality of power semiconductor chips of IGBTs or FETs are fixed to copper circuits, wherein a thermistor is disposed in a position near the power semiconductor chip on the copper circuit, and the thermistor is electrically connected to the gate of the power semiconductor chip, increasing the gate resistance value when the temperature of the power semiconductor chip is high, and reducing the gate resistance value when the temperature of the power semiconductor chip is low (for example, refer to JP-A-2003-188336).
However, the heretofore known example described in JP-A-2006-41407 is such that a temperature detection element is disposed in the vicinity of a power semiconductor element, and as all the gates of a plurality of power semiconductor elements are turned off when the temperature detected by the temperature detection element is equal to or higher than a decision temperature, there is an unsolved problem in that it is not possible to individually control the gates of the plurality of power semiconductor elements in accordance with the exothermic temperature.
Also, the heretofore known example described in JP-A-2006-191774 is such that, as the gate resistance value of an IGBT element with good cooling efficiency is set high in comparison with the gate resistance value of an IGBT element with poor cooling efficiency when a plurality of IGBT elements are present, it is possible to control individually in accordance with the IGBT element temperature, but it is necessary to set a different resistance value for each IGBT element, and the gate resistor has temperature characteristics such that the resistance value increases in response to an increase in temperature, because of which there is an unsolved problem in that it is difficult to obtain a set resistance value.
Furthermore, the heretofore known example described in JP-A-2003-188336 is such that it is necessary to use a thermistor having negative resistance characteristics wherein the resistance value decreases further the higher the temperature becomes, and it is difficult to obtain the resistance characteristics necessary for the gate resistor with the thermistor alone, because of which it is necessary to obtain the resistance characteristics necessary for the gate resistor with a combined resistance by disposing a series circuit of the thermistor and a resistor and a resistor in parallel with the series circuit, and there is an unsolved problem in that the resistor configuration becomes complex.